Name-based routing is a present paradigm for network routing. Name-based routing has served the traditional “host-to-host” communication model for many years. Name-oriented networking efforts include Content-Centric Network (CCN) and Named data Networking (NDN). However, a paradigm shift from a “host-to-host” model to a “host-to-content” or “host-to-information” model appears imminent. The CCN and NDN have attempted to adopt name-based routing to enable the “host-to-content” communication model, specifically, by utilizing content objects with structured names. In name-based routing, e.g., CCN and NDN, a content origin or source that owns original content objects may announce name prefixes into the network. Such announcements may be propagated throughout the network via intra-domain routing protocols, such as Open Shortest Path First (OSPF). A Forward Information Base (FIB) in each router may store to which interface (“face”) the router may forward any request for a named content matching a given name prefix. Upon receiving name prefix announcements, each router may update the corresponding FIB accordingly. Clients may send interest packets requesting for interested content, and the network may respond with data packets of the requested content. The CCN and NDN may also use other components, such as a Content Store (CS) and a Pending interest Table (PIT). The CS may be used to store cacheable content objects for efficient content distribution, and the PIT may be used to aggregate pending interests for the same content and propagate data packets, e.g., in a multicast manner, towards the requesting clients.
However, name-based routing in CCNs (and NDNs) may also pose challenges to network scalability. In current CCN design, content origins (or their first-hop routers) may have to be propagated throughout the network via either intra-domain protocols, such as OSPF, or similar protocols, e.g., similar to how Internet Protocol (IP) prefixes are announced in an intra-domain network. This scheme is referred to herein as the proactive routing scheme. However, the number of distinct name prefixes of future systems is expected to be large, even after aggressive aggregation. Propagating large numbers of name prefixes may be challenging since this may overload routers and consume a substantial portion of network bandwidth. Additionally, the number of name prefixes may be multiple orders of magnitude larger than what the conventional FIB may store, thus the FIB may only store a subset or a portion of name prefixes. As a result, the FIB may miss when the FIB has no knowledge about where to forward interests. Such misses may be common and name-based routing may heavily rely on fallback schemes, e.g., broadcast interests, to address FIB misses, degrading network performance and user experiences. Further, the fallback scheme adopted in CCN may become another cause for overloading routers, consuming a significant portion of network bandwidth, and degrading network performance.
Reusing intra-domain routing protocols (e.g., OSPF with CCN adaptation) has been proposed to propagate name prefixes to all routers in an intra-domain network. However, the number of name prefixes is likely to increase at least at the scale of domain names in the Internet. Re-using OSPF-like protocols may lead to further network scalability challenges. For instance, in the case of domain names with an average length of about 16 bytes, announcements of about 0.5 billion domain names may generate 8×109 bytes of traffic. If those names are announced in about 1-minute intervals, then for each network link, the average bandwidth consumed by periodical active announcements may be about 1 Giga bits per second (Gbps). Moreover, the number of name prefixes may be larger than the number of domain names, e.g., 10 times larger, yielding a bandwidth consumption due to name prefix announcement as high as about 10 Gbps.